Yamaha RAPTOR YFM660R Owner's Manual page 296

a. Spark plug gap
a. Écartement des électrodes
a. Separación entre electrodos de la bujía
Before installing the spark plug, measure the
electrode gap with a feeler gauge and adjust to
specification.
Spark plug gap:
0.8 ~ 0.9 mm
When installing the spark plug, always clean
the gasket surface and use a new gasket. Wipe
off any grime from the threads and tighten to
the specified torque.
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kg)
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